The present proposal requests supplemental funds for the Program Project Grant that presently supports the Rocky Mountain Taste and Smell Center. The investigators are all, save Dr. Kinnamon, Faculty members housed within the same building in the University of Colorado School of Medicine in Denver, Colorado. The Center will consist of the laboratories and personnel of the five principal investigators, a system of mutually shared Core facilities, and the Otorhinolaryngology clinic at University Hospital directly adjacent to the School of Medicine. The major objective of the proposed Program Project is to increase the fundamental knowledge and understanding of the neurobiological substrates of the senses of taste and smell and their disorders at the cellular level. That objective will be accomplished through a series of five major projects: 1) Biomedical investigations of vertebrate olfactory mucosa, David T. Moran, P.I.; 2)\Chemosensory transduction in vertebrate taste buds, Stephen D. Roper, P.I.; 3) Anatomical analysis of electrophysiologically identified primary gustatory afferents, Thomas E. Finger, P.I.; 4) Neurobiology of normal and abnormal human gustatory receptors, Bruce W. Jafek, P.I.; and 5)\Ultrastructure of vertebrate taste buds, John C. Kinnamon, P.I. These investigations will utilize a number of powerful new approaches--such as intracellular recording from taste receptors and computer-generated three-dimensional structure analysis of high voltage electron micrographs of olfactory and taste receptors, to name but two--to elucidate the cellular neurobiology of taste and smell receptors. At the University of Colorado we are fortunate to have excellent equipment, facilities, ample laboratory and clinic space, and personnel already in place. The five principal investigators are all exceptionally well-qualified biomedical scientists trained in a variety of major neurobiological disciplines including electron microscopy, electrophysiology, neuroanatomy, surgery, and cell biology. The interrelationship between the investigators, investigations, and shared facilities is so close that, in the present Program Project, the whole will emerge far greatr than the sum of its component parts.